/*
 * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */
package javax.swing;


import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.beans.*;
import javax.swing.event.*;

import sun.awt.EmbeddedFrame;

/**
 * The KeyboardManager class is used to help dispatch keyboard actions for the
 * WHEN_IN_FOCUSED_WINDOW style actions.  Actions with other conditions are handled
 * directly in JComponent.
 * <p>
 * Here's a description of the symantics of how keyboard dispatching should work
 * atleast as I understand it.
 * <p>
 * KeyEvents are dispatched to the focused component.  The focus manager gets first
 * crack at processing this event.  If the focus manager doesn't want it, then
 * the JComponent calls super.processKeyEvent() this allows listeners a chance
 * to process the event.
 * <p>
 * If none of the listeners "consumes" the event then the keybindings get a shot.
 * This is where things start to get interesting.  First, KeyStokes defined with the
 * WHEN_FOCUSED condition get a chance.  If none of these want the event, then the component
 * walks though it's parents looked for actions of type WHEN_ANCESTOR_OF_FOCUSED_COMPONENT.
 * <p>
 * If no one has taken it yet, then it winds up here.  We then look for components registered
 * for WHEN_IN_FOCUSED_WINDOW events and fire to them.  Note that if none of those are found
 * then we pass the event to the menubars and let them have a crack at it.  They're handled differently.
 * <p>
 * Lastly, we check if we're looking at an internal frame.  If we are and no one wanted the event
 * then we move up to the InternalFrame's creator and see if anyone wants the event (and so on and so on).
 *
 * @see InputMap
 */
class KeyboardManager {

    static KeyboardManager currentManager = new KeyboardManager();

    /**
     * maps top-level containers to a sub-hashtable full of keystrokes
     */
    Hashtable<Container, Hashtable> containerMap = new Hashtable<Container, Hashtable>();

    /**
     * Maps component/keystroke pairs to a topLevel container
     * This is mainly used for fast unregister operations
     */
    Hashtable<ComponentKeyStrokePair, Container> componentKeyStrokeMap = new Hashtable<ComponentKeyStrokePair, Container>();

    public static KeyboardManager getCurrentManager() {
        return currentManager;
    }

    public static void setCurrentManager(KeyboardManager km) {
        currentManager = km;
    }

    /**
     * register keystrokes here which are for the WHEN_IN_FOCUSED_WINDOW
     * case.
     * Other types of keystrokes will be handled by walking the hierarchy
     * That simplifies some potentially hairy stuff.
     */
    public void registerKeyStroke(KeyStroke k, JComponent c) {
        Container topContainer = getTopAncestor(c);
        if (topContainer == null) {
            return;
        }
        Hashtable keyMap = containerMap.get(topContainer);

        if (keyMap == null) {  // lazy evaluate one
            keyMap = registerNewTopContainer(topContainer);
        }

        Object tmp = keyMap.get(k);
        if (tmp == null) {
            keyMap.put(k, c);
        } else if (tmp instanceof Vector) {  // if there's a Vector there then add to it.
            Vector v = (Vector) tmp;
            if (!v.contains(c)) {  // only add if this keystroke isn't registered for this component
                v.addElement(c);
            }
        } else if (tmp instanceof JComponent) {
            // if a JComponent is there then remove it and replace it with a vector
            // Then add the old compoennt and the new compoent to the vector
            // then insert the vector in the table
            if (tmp != c) {  // this means this is already registered for this component, no need to dup
                Vector<JComponent> v = new Vector<JComponent>();
                v.addElement((JComponent) tmp);
                v.addElement(c);
                keyMap.put(k, v);
            }
        } else {
            System.out.println("Unexpected condition in registerKeyStroke");
            Thread.dumpStack();
        }

        componentKeyStrokeMap.put(new ComponentKeyStrokePair(c, k), topContainer);

        // Check for EmbeddedFrame case, they know how to process accelerators even
        // when focus is not in Java
        if (topContainer instanceof EmbeddedFrame) {
            ((EmbeddedFrame) topContainer).registerAccelerator(k);
        }
    }

    /**
     * Find the top focusable Window, Applet, or InternalFrame
     */
    private static Container getTopAncestor(JComponent c) {
        for (Container p = c.getParent(); p != null; p = p.getParent()) {
            if (p instanceof Window && ((Window) p).isFocusableWindow() ||
                    p instanceof Applet || p instanceof JInternalFrame) {

                return p;
            }
        }
        return null;
    }

    public void unregisterKeyStroke(KeyStroke ks, JComponent c) {

        // component may have already been removed from the hierarchy, we
        // need to look up the container using the componentKeyStrokeMap.

        ComponentKeyStrokePair ckp = new ComponentKeyStrokePair(c, ks);

        Container topContainer = componentKeyStrokeMap.get(ckp);

        if (topContainer == null) {  // never heard of this pairing, so bail
            return;
        }

        Hashtable keyMap = containerMap.get(topContainer);
        if (keyMap == null) { // this should never happen, but I'm being safe
            Thread.dumpStack();
            return;
        }

        Object tmp = keyMap.get(ks);
        if (tmp == null) {  // this should never happen, but I'm being safe
            Thread.dumpStack();
            return;
        }

        if (tmp instanceof JComponent && tmp == c) {
            keyMap.remove(ks);  // remove the KeyStroke from the Map
            //System.out.println("removed a stroke" + ks);
        } else if (tmp instanceof Vector) {  // this means there is more than one component reg for this key
            Vector v = (Vector) tmp;
            v.removeElement(c);
            if (v.isEmpty()) {
                keyMap.remove(ks);  // remove the KeyStroke from the Map
                //System.out.println("removed a ks vector");
            }
        }

        if (keyMap.isEmpty()) {  // if no more bindings in this table
            containerMap.remove(topContainer);  // remove table to enable GC
            //System.out.println("removed a container");
        }

        componentKeyStrokeMap.remove(ckp);

        // Check for EmbeddedFrame case, they know how to process accelerators even
        // when focus is not in Java
        if (topContainer instanceof EmbeddedFrame) {
            ((EmbeddedFrame) topContainer).unregisterAccelerator(ks);
        }
    }

    /**
     * This method is called when the focused component (and none of
     * its ancestors) want the key event.  This will look up the keystroke
     * to see if any chidren (or subchildren) of the specified container
     * want a crack at the event.
     * If one of them wants it, then it will "DO-THE-RIGHT-THING"
     */
    public boolean fireKeyboardAction(KeyEvent e, boolean pressed, Container topAncestor) {

        if (e.isConsumed()) {
            System.out.println("Acquired pre-used event!");
            Thread.dumpStack();
        }

        // There may be two keystrokes associated with a low-level key event;
        // in this case a keystroke made of an extended key code has a priority.
        KeyStroke ks;
        KeyStroke ksE = null;


        if (e.getID() == KeyEvent.KEY_TYPED) {
            ks = KeyStroke.getKeyStroke(e.getKeyChar());
        } else {
            if (e.getKeyCode() != e.getExtendedKeyCode()) {
                ksE = KeyStroke.getKeyStroke(e.getExtendedKeyCode(), e.getModifiers(), !pressed);
            }
            ks = KeyStroke.getKeyStroke(e.getKeyCode(), e.getModifiers(), !pressed);
        }

        Hashtable keyMap = containerMap.get(topAncestor);
        if (keyMap != null) { // this container isn't registered, so bail

            Object tmp = null;
            // extended code has priority
            if (ksE != null) {
                tmp = keyMap.get(ksE);
                if (tmp != null) {
                    ks = ksE;
                }
            }
            if (tmp == null) {
                tmp = keyMap.get(ks);
            }

            if (tmp == null) {
                // don't do anything
            } else if (tmp instanceof JComponent) {
                JComponent c = (JComponent) tmp;
                if (c.isShowing() && c.isEnabled()) { // only give it out if enabled and visible
                    fireBinding(c, ks, e, pressed);
                }
            } else if (tmp instanceof Vector) { //more than one comp registered for this
                Vector v = (Vector) tmp;
                // There is no well defined order for WHEN_IN_FOCUSED_WINDOW
                // bindings, but we give precedence to those bindings just
                // added. This is done so that JMenus WHEN_IN_FOCUSED_WINDOW
                // bindings are accessed before those of the JRootPane (they
                // both have a WHEN_IN_FOCUSED_WINDOW binding for enter).
                for (int counter = v.size() - 1; counter >= 0; counter--) {
                    JComponent c = (JComponent) v.elementAt(counter);
                    //System.out.println("Trying collision: " + c + " vector = "+ v.size());
                    if (c.isShowing() && c.isEnabled()) { // don't want to give these out
                        fireBinding(c, ks, e, pressed);
                        if (e.isConsumed())
                            return true;
                    }
                }
            } else {
                System.out.println("Unexpected condition in fireKeyboardAction " + tmp);
                // This means that tmp wasn't null, a JComponent, or a Vector.  What is it?
                Thread.dumpStack();
            }
        }

        if (e.isConsumed()) {
            return true;
        }
        // if no one else handled it, then give the menus a crack
        // The're handled differently.  The key is to let any JMenuBars
        // process the event
        if (keyMap != null) {
            Vector v = (Vector) keyMap.get(JMenuBar.class);
            if (v != null) {
                Enumeration iter = v.elements();
                while (iter.hasMoreElements()) {
                    JMenuBar mb = (JMenuBar) iter.nextElement();
                    if (mb.isShowing() && mb.isEnabled()) { // don't want to give these out
                        boolean extended = (ksE != null) && !ksE.equals(ks);
                        if (extended) {
                            fireBinding(mb, ksE, e, pressed);
                        }
                        if (!extended || !e.isConsumed()) {
                            fireBinding(mb, ks, e, pressed);
                        }
                        if (e.isConsumed()) {
                            return true;
                        }
                    }
                }
            }
        }

        return e.isConsumed();
    }

    void fireBinding(JComponent c, KeyStroke ks, KeyEvent e, boolean pressed) {
        if (c.processKeyBinding(ks, e, JComponent.WHEN_IN_FOCUSED_WINDOW,
                pressed)) {
            e.consume();
        }
    }

    public void registerMenuBar(JMenuBar mb) {
        Container top = getTopAncestor(mb);
        if (top == null) {
            return;
        }
        Hashtable keyMap = containerMap.get(top);

        if (keyMap == null) {  // lazy evaluate one
            keyMap = registerNewTopContainer(top);
        }
        // use the menubar class as the key
        Vector menuBars = (Vector) keyMap.get(JMenuBar.class);

        if (menuBars == null) {  // if we don't have a list of menubars,
            // then make one.
            menuBars = new Vector();
            keyMap.put(JMenuBar.class, menuBars);
        }

        if (!menuBars.contains(mb)) {
            menuBars.addElement(mb);
        }
    }


    public void unregisterMenuBar(JMenuBar mb) {
        Container topContainer = getTopAncestor(mb);
        if (topContainer == null) {
            return;
        }
        Hashtable keyMap = containerMap.get(topContainer);
        if (keyMap != null) {
            Vector v = (Vector) keyMap.get(JMenuBar.class);
            if (v != null) {
                v.removeElement(mb);
                if (v.isEmpty()) {
                    keyMap.remove(JMenuBar.class);
                    if (keyMap.isEmpty()) {
                        // remove table to enable GC
                        containerMap.remove(topContainer);
                    }
                }
            }
        }
    }

    protected Hashtable registerNewTopContainer(Container topContainer) {
        Hashtable keyMap = new Hashtable();
        containerMap.put(topContainer, keyMap);
        return keyMap;
    }

    /**
     * This class is used to create keys for a hashtable
     * which looks up topContainers based on component, keystroke pairs
     * This is used to make unregistering KeyStrokes fast
     */
    class ComponentKeyStrokePair {
        Object component;
        Object keyStroke;

        public ComponentKeyStrokePair(Object comp, Object key) {
            component = comp;
            keyStroke = key;
        }

        public boolean equals(Object o) {
            if (!(o instanceof ComponentKeyStrokePair)) {
                return false;
            }
            ComponentKeyStrokePair ckp = (ComponentKeyStrokePair) o;
            return ((component.equals(ckp.component)) && (keyStroke.equals(ckp.keyStroke)));
        }

        public int hashCode() {
            return component.hashCode() * keyStroke.hashCode();
        }

    }

} // end KeyboardManager
